US researchers have revealed that the risk of asthma is elevated in children whose mothers smoked during pregnancy. This is due to the changes in DNA caused by smoking.
Researchers explained the process of DNA methylation which changes the normal functioning of the gene. The changed genes are passed on from mother to fetus.
"We found that children exposed to maternal smoking in utero had a 2.3 percent increase in DNA methylation in AXL.These results confirm results from a prior study and present compelling evidence that environmental exposure to tobacco smoke during pregnancy may alter DNA methylation levels," Carrie Breton, assistant professor of preventive medicine at The Keck School of Medicine of the University of Southern California, Los Angeles, said.